It seems as though my car only overheats after 20+ min of me driving it. When I get home, the reservoir is usually full of coolant (sometimes you can see it has overflowed).

Also, the faster I go, the more the temp gauge goes down whenever the car decides to overheat. lmao.. The hell?

I just installed a new thermostat, radiator cap and new radiator. All OEM.

No white smoke. No milky coolant. Fan comes on. When bleeding my coolant today, I did see slight steam/smoke coming from the reservoir/reservoir tube.

D16 ZC Non Vtec

 

MM&Y of car?
How many miles on the engine? 94

 

check that both fans are running simultaneously

 

60-70K on engine.

95 Civic EJ

 

It only has one fan for the radiator and it comes on. Not sure if there is a specific length of time it should stay on, but it does come on (about 10 secs).

 

Bump. Anyone?

 

So I did this, and my fan comes on.

Does this mean that I have a bad fan switch or everything is running like it is supposed to?

Looking back, I want to say that my car only overheats after I stop for a while
.
I then have to drive fast as fukk to get the temperature gauge down.

 

You jumped the fan switch and it turned on, that shows fans work. Take the plugs out and make sure the cylinders are dry, but I would say if you have to drive fast or rev the motor, sounds like a water pump.

I didn't do that lol^^^^

 

I was thinking water pump too. However, I thought a bad water pump would leak before anything. Also, when I take the spark plugs out, what am I looking for (oil, coolant, etc)?

 

If you replaced the radiator and it's still doin it, I'm thinking the water pump fins might be worn. Do you ever use tap water ?

 

50/50 coolant since I got the engine.

 

I agree, it is most likely the pump.

Question, you said, "but it does come on (about 10 secs", does that mean it only stays on for that 10sec and then turns off and keeps running with jumper in place, replace ECT switch. 94

 

When I was bleeding my system, the fan did come on. It stayed for about 10 seconds, and then cut off. When I had the jumper in the fan switch, the fan continuously ran. Does this mean I have a bad fan switch, or everything is working like it's supposed to?

 

if the fans run when the car is overheating the fan switch is likely ok but they shouldnt be turning off

the next time it starts rising and the fans turn off, i would quickly jumper the fan switch and leave the fan on to see if the temp goes down, if it does then replace the fan switch with a Honda fan switch

 

wait, now im thinking the thermostat might be bad, idle the car and check the lower radiator hose back where it meets the thermostat housing, make sure it gets hot as the car warms up, it might not be and that would mean you need a new Honda thermostat

 

I can confirm that the bottom hose gets hot at operating temperature. I just changed it three days ago.
Should the bottom hose be full of coolant though?
https://youtu.be/GYmrxzwYm4I

 

Yes of course that hose will get full with coolaant. You changed the thermostat ? Did you crack open the bleeder bolt when filling the radiator ?

 

Indeed. I spent hours bleeding the system via the the bleeder bolt and taking the cap off letting the car run.

 

ok compression test the engine

 

A pump will leak when the bushings are going bad. I've seen the fins completely gone eaten by straight water. Your looking for coolent in the cylinders. It'll be pretty obvious.

 

Thanks for replying! I've heard about the fins being eaten off from corrosion. I just don't see how it's possible since all I've been using is 50/50. Still a possibility I would assume. And definitely going to look for coolant in the cylinder head.

 

A $20 compression test would rule out a failing head gasket and prevent you from having to pull the head. Then you would just pull the water pump to see if they are indeed bad. It is possible you have a hairline crack in the block but this isn't all too common.

 

Happend to my accord. Same symptoms....blown headgasket. Exhaust gases is pushing coolant back out into the resivior. When engine cools, coolant remains in resivior and radiator is low. Drive and repeat....but yes def do a pressure test.

 

Kinda. The coolant in the reservoir goes down overnight. And the radiator stays full. Definitely going to do a pressure test.

 

This indicates your cap is working properly.

When you bled the system did you make sure the nose of the car was raised some? i.e. parked on an incline with the nose up?